Recent improvements in printing have concentrated on increasing the speed of printing pages. In an electrophotographic printer, multiple light beams from a light emitter array may be used to increase print speed by forming swaths of scan lines. If the scan lines in a swath are not properly spaced, banding occurs. Banding lowers print quality.
The spacing of the scan lines is precisely aligned in an exposure module of the printer that is sent to the user. The module may be shipped with the printer. The module may become misaligned in shipping, printer setup, printer operation, and the like. The misalignment may be due to temperature variations, vibration, pressure, or other factors. If the printer exhibits banding, the module is removed from the printer and sent to a laboratory especially equipped for precisely aligning the exposure module. Removing and realigning the module is costly. The act of realigning the exposure module may not eliminate, nor minimize, nor guarantee the future absence of banding. When the exposure module is removed, the printer may be unavailable for use.
Therefore, there is a need for adjusting scan line spacing in electrophotographic printers which have multiple light beams. There is also a need to avoid the costly process of removing and realigning the exposure module. Furthermore, there is a need to improve the availability of the printer for use.